Your IP : 216.73.216.1
//===-- AdornedCFG.h ------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines an AdornedCFG class that is used by dataflow analyses that
// run over Control-Flow Graphs (CFGs).
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_ADORNEDCFG_H
#define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_ADORNEDCFG_H
#include "clang/AST/ASTContext.h"
#include "clang/AST/Decl.h"
#include "clang/AST/Stmt.h"
#include "clang/Analysis/CFG.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Support/Error.h"
#include <memory>
#include <utility>
namespace clang {
namespace dataflow {
/// Holds CFG with additional information derived from it that is needed to
/// perform dataflow analysis.
class AdornedCFG {
public:
/// Builds an `AdornedCFG` from a `FunctionDecl`.
/// `Func.doesThisDeclarationHaveABody()` must be true, and
/// `Func.isTemplated()` must be false.
static llvm::Expected<AdornedCFG> build(const FunctionDecl &Func);
/// Builds an `AdornedCFG` from an AST node. `D` is the function in which
/// `S` resides. `D.isTemplated()` must be false.
static llvm::Expected<AdornedCFG> build(const Decl &D, Stmt &S,
ASTContext &C);
/// Returns the `Decl` containing the statement used to construct the CFG, if
/// available.
const Decl &getDecl() const { return ContainingDecl; }
/// Returns the CFG that is stored in this context.
const CFG &getCFG() const { return *Cfg; }
/// Returns a mapping from statements to basic blocks that contain them.
const llvm::DenseMap<const Stmt *, const CFGBlock *> &getStmtToBlock() const {
return StmtToBlock;
}
/// Returns whether `B` is reachable from the entry block.
bool isBlockReachable(const CFGBlock &B) const {
return BlockReachable[B.getBlockID()];
}
/// Returns whether `B` contains an expression that is consumed in a
/// different block than `B` (i.e. the parent of the expression is in a
/// different block).
/// This happens if there is control flow within a full-expression (triggered
/// by `&&`, `||`, or the conditional operator). Note that the operands of
/// these operators are not the only expressions that can be consumed in a
/// different block. For example, in the function call
/// `f(&i, cond() ? 1 : 0)`, `&i` is in a different block than the `CallExpr`.
bool containsExprConsumedInDifferentBlock(const CFGBlock &B) const {
return ContainsExprConsumedInDifferentBlock.contains(&B);
}
private:
AdornedCFG(
const Decl &D, std::unique_ptr<CFG> Cfg,
llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock,
llvm::BitVector BlockReachable,
llvm::DenseSet<const CFGBlock *> ContainsExprConsumedInDifferentBlock)
: ContainingDecl(D), Cfg(std::move(Cfg)),
StmtToBlock(std::move(StmtToBlock)),
BlockReachable(std::move(BlockReachable)),
ContainsExprConsumedInDifferentBlock(
std::move(ContainsExprConsumedInDifferentBlock)) {}
/// The `Decl` containing the statement used to construct the CFG.
const Decl &ContainingDecl;
std::unique_ptr<CFG> Cfg;
llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock;
llvm::BitVector BlockReachable;
llvm::DenseSet<const CFGBlock *> ContainsExprConsumedInDifferentBlock;
};
} // namespace dataflow
} // namespace clang
#endif // LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_ADORNEDCFG_H